Structure of a typical vertebra

A typical vertebra is composed of the following three elements:

Vertebral body (corpus vertebrae) the anterior, bigger and stronger part of the vertebra. It exists in all vertebrae except the first cervical vertebra. The vertebral body consists of two parts:

Intervertebral surface

Intervertebral surface (facies intervertebralis) which is the central part of the body with concavity on its

superior and inferior surface.

Anular epiphysis

Anular epiphysis (epiphysis annularis) which is a peripherally elevated ring at the superior and inferior

surfaces of the vertebral body.

Vertebral arch (arcus vertebrae) forms protection for the spinal cord and it is the reason that it could also be called the neural arch. It is the posterior part of the vertebra which consists of:

Pedicle of vertebral arch

Pedicle of vertebral arch (pedunculus arcus vertebrae) which projects posterolaterally from the body and it is fused with the second one in the midline. On the pedicles of the following structures that may be identified:

  • The superior vertebral notch (smaller) and the inferior vertebral notch (deeper) which form the in-tervertebral foramen (made up of the inferior vertebral notch from vertebra above and the superior vertebral notch from the vertebra below) when the vertebrae are articulated. The intervertebral foramen is a space between pedicles of adjacent vertebrae for passage of the spinal nerve (see Fig. 2-33)

Lamina of vertebral arch

Lamina of vertebral arch (lamina arcus vertebrae) extends posteromedialy from pedicle of vertebral arch, and it connects with the second one in the midline.

There are seven processess (three types), which arise from the vertebral arch.

  • Spinous process (processus spinosus) is an unpaired process which projects backwardly in the midsagittal plane from the union point of the vertebral arch laminae
  • Transverse process (processus transversus) is a paired process which projects laterally on each side from the junction of the lamina and pedicle. They form bony levers for the attachment of deep back muscles.
  • Superior articular process (processus articularis superior) is a paired process and it projects superiorly on each of the pedicle (it projects superiorly and in different regions, the superior, anterior or medial articular surface is found on it for the cervical, thoracic and lumbar vertebrae respectively).
  • Inferior articular process (processus articularis inferior) is a paired process that projects inferiorly on each side of the pedicle (it project inferiorly and in different regions, the inferior, posterior or lateral articular surface is found on it for the cervical, thoracic and lumbar vertebrae respectively).

Vertebral foramen

Vertebral foramen (foramen vertebrale) is a space surrounded by the body from posterior and arch of the vertebra from lateral and anterior side through which the spinal cord descends.

Clinical comments

Spina bifida (spina bifida) is a complex birth defect in which there is incomplete development of the laminae of the vertebral arch. If only the vertebral lamina is undeveloped and the spinal cord is intact without any skin abnormalities, this malformation is called spina bifida occulta and it occurs in 5% of the population. Most clinical cases of vertebral lamina defects are concurrent with meningeal defects and are called meningocoele which is a prolapse of the meninges. If the spinal cord and meninges are prolapsed it is called meningomyelocoele. The presence of this neurological defect after birth requires urgent neurosurgical intervention.